/*========================== begin_copyright_notice ============================

Copyright (C) 2020-2021 Intel Corporation

SPDX-License-Identifier: MIT

============================= end_copyright_notice ===========================*/

#ifndef IGA_MESSAGE_INFO_HPP
#define IGA_MESSAGE_INFO_HPP

#include "../Backend/Native/Field.hpp"
#include "../IR/Instruction.hpp"
#include "../api/iga_bxml_enums.hpp"

#include <cstdint>
#include <string>
#include <tuple>
#include <vector>

namespace iga {
struct DescField {
  DescField(int _off, int _len) : off(_off), len(_len) {}
  int off, len;
};

using DiagnosticList = std::vector<std::pair<DescField, std::string>>;
using DecodedDescFields =
    std::vector<std::tuple<Fragment, uint32_t, std::string>>;

// This is generic list of send operations.  One or more messages may map
// to the same element (hence why "generic").  In other words, two
// different units (maybe different hardware generate the same message).
enum class SendOp {
  INVALID,
#define DEFINE_SEND_OP(E, M, D, A) E,
#include "EnumSendOpInfo.hpp"
#undef DEFINE_SEND_OP
};

struct SendOpDefinition {
  SendOp op;
  const char *mnemonic;    // e.g. "load" for SendOp::LOAD
  const char *description; // a longer description

  // typesafe bitset of send op attributes
  enum class Attr {
    NONE = 0x0000,
    //
    // the may have a destination (e.g. loads or atomics)
    // certain control ops may or may not have destinations
    HAS_DST = 0x0001,
    //
    // is the address a scalar register (e.g. load_block)
    IS_SCALAR_ADDR = 0x0002,
    //
    // if the operation supports a ChMask (e.g. load_quad)
    HAS_CMASK = 0x0004,
    //
    // If the message is a sampler gather4
    GATHER4 = 0x0008,
    //
    // the op is a load, store, or atomic
    GROUP_LOAD = 0x0010,
    GROUP_STORE = 0x0020,
    GROUP_ATOMIC = 0x0040,
    GROUP_SAMPLE = 0x0080,
    GROUP_OTHER = 0x0100, // e.g. fence, barrier, eot, etc...

    // for atomics, the number of data arguments in src1
    ATOMIC_UNARY = 0x1000,   // none (atomic_iinc)
    ATOMIC_BINARY = 0x2000,  // one (atomic_fadd)
    ATOMIC_TERNARY = 0x4000, // two (atomic_icas)
  };
  Attr attrs;

  constexpr SendOpDefinition(SendOp o, const char *mne, const char *desc,
                             Attr _attrs = Attr::NONE)
      : op(o), mnemonic(mne), description(desc), attrs(_attrs) {}
  constexpr SendOpDefinition(const SendOpDefinition &) = delete;
  constexpr SendOpDefinition &operator=(const SendOpDefinition &) = delete;

  bool isValid() const { return op != SendOp::INVALID; }
  bool hasAttr(Attr a) const { return (((int)attrs & (int)a)) != 0; }

  bool hasDst() const { return hasAttr(Attr::HAS_DST); }
  bool hasChMask() const { return hasAttr(Attr::HAS_CMASK); }
  bool isAddressScalar() const { return hasAttr(Attr::IS_SCALAR_ADDR); }

  bool isLoad() const { return hasAttr(Attr::GROUP_LOAD); }
  bool isStore() const { return hasAttr(Attr::GROUP_STORE); }
  bool isAtomic() const { return hasAttr(Attr::GROUP_ATOMIC); }
  bool isSample() const { return hasAttr(Attr::GROUP_SAMPLE); }
  bool isOther() const { return hasAttr(Attr::GROUP_OTHER); }

  int numAtomicArgs() const {
    return hasAttr(Attr::ATOMIC_UNARY)     ? 0
           : hasAttr(Attr::ATOMIC_BINARY)  ? 1
           : hasAttr(Attr::ATOMIC_TERNARY) ? 2
                                           : -1;
  }
}; // SendOpDefinition
static inline constexpr SendOpDefinition::Attr
operator|(SendOpDefinition::Attr a1, SendOpDefinition::Attr a2) {
  return SendOpDefinition::Attr(int(a1) | int(a2));
}

const SendOpDefinition &lookupSendOp(SendOp op);
const SendOpDefinition &lookupSendOp(const char *mnemonic);

std::string ToSyntax(SendOp op);

enum class AddrType {
  // the invalid value
  INVALID = 0,
  // stateless
  FLAT,
  // stateful: bindless surface state (UMD)
  BSS,
  // stateful: surface state (KMD)
  SS,
  // stateful: binding table interface
  BTI,
};
std::string ToSymbol(AddrType op);

// documentation reference
struct DocRef {
  enum Kind {
    INVALID = 0,
    //
    DST,  // load or atomic payload
    SRC0, // headers/addresses etc...
    SRC1, // store/atomic payload
    //
    MSGOP,  // the message opcode (always bits of the descriptor)
    DESC,   // descriptor
    EXDESC, // extended descriptor (imm or reg)
  } kind;
  // the documentation symbol name corresponding to this
  const char *symbol;
  const char *link;
  constexpr DocRef() : DocRef(DocRef::INVALID, nullptr, nullptr) {}
  constexpr DocRef(Kind _kind, const char *sym, const char *lnk)
      : kind(_kind), symbol(sym), link(lnk) {}
};

///////////////////////////////////////////////////////////////////////////
// Generic processing of basic buffer messages.   This includes data port
// vector reads and writes as well block and atomic messages.  There may be
// certain obscure or legacy operations that are unsupported.
//
struct MessageInfo {
  enum class Attr : uint32_t {
    NONE = 0x0,
    //
    // Set on atomic operations that return data.
    ATOMIC_RETURNS = 1 << 0,
    //
    // For messages that uncompress data, expand into the high unit
    // instead of the low.
    EXPAND_HIGH = 1 << 1,
    //
    // If the message supports a channel mask for vector size
    // (data elements)
    HAS_CHMASK = 1 << 2,
    //
    // Indicates the message is has U, V, R, and LOD coordinates
    // as part of the address payloads.
    // Otherw messages may have a different coordinate layout.
    HAS_UVRLOD = 1 << 3,
    //
    // Indicates a scratch message
    SCRATCH = 1 << 4,
    //
    // Indicates the message is to SLM (shared local memory)
    SLM = 1 << 5,
    //
    // Indicates the data is transposed during load or store.
    TRANSPOSED = 1 << 6,
    //
    // Indicates the message is a typed operation.
    // In later platforms this implies the operation is to SFID TGM.
    TYPED = 1 << 7,
    //
    // Indicates the message decode info is valid.
    VALID = 0x80000000,
  };

  //
  // Queries a boolean property of this message.
  bool hasAttr(Attr attr) const;
  // Adds attributes to the attribute set.
  void addAttr(Attr attr);

  // The specific operation
  SendOp op = SendOp::INVALID;

  // A bitset of the above attributes
  Attr attributeSet = MessageInfo::Attr::NONE;

  // Size (in bits) of one address
  int addrSizeBits = 0;
  //
  // The size (in bits) of each element once stored in the register file.
  int elemSizeBitsRegFile = 0;
  //
  // The size (in bits) of each element in memory.
  //
  // This can differ from elemSizeRegisterFile if there's any compression
  // effects.  For example, a byte gathering read will load one, two,
  // four bytes into each 32b slot leaving the upper bits for the one-
  // and two-byte case.
  //
  int elemSizeBitsMemory = 0;
  //
  // The number of vector elems or active channels in the cmask.
  // This is the number of elements each address loads.
  //
  // For example a legacy untyped load with a channel mask of XYZ
  // would be 3.  Some scatter/gather messages have a SIMT vector
  // component similar in function.
  int elemsPerAddr = 0;
  //
  // For LOAD_QUAD and STORE_QUAD, this holds a bit mask of up to four
  // bits with which channels are *enabled* (not disabled).
  //
  // The elemsPerAddr field will still be set
  // (with the set cardinality here).
  int channelsEnabled = 0;
  //
  // The number of channels in the size of the operation.
  // (The "SIMD" size.)
  int execWidth = 0;

  // Caching options for the L1 cache (if supported)
  CacheOpt cachingL1 = CacheOpt::INVALID;
  //
  // Caching options for the L3 cache (if supported)
  // In some HDC messages this is bit 13.  Some parts don't
  // implement it though.
  CacheOpt cachingL3 = CacheOpt::INVALID;
  //
  // The surface addressing model
  AddrType addrType = AddrType::INVALID;
  //
  // The surface identifier (if applicable).  E.g. BTI.
  SendDesc surfaceId;
  //
  // Possible immediate offset (if the encoding supports it)
  // This is in bytes not elements
  int immediateOffset = 0;
  //
  // same as the above but only for block2d (mutally exclusive with above)
  // This is in dataSize elements
  int immediateOffsetBlock2dX = 0, immediateOffsetBlock2dY = 0;
  //
  // A symbol value for this message (syntax).
  // The syntax is not complete and IGA will not consume it directly
  // (since some information isn't in necessarily in the descriptors).
  std::string symbol;
  //
  //
  // This may hold a useful string telling the user the exact message
  // matching this specification up decode (if it exists).  This is
  // indended for for debugging only; the value and behavior are subject
  // to change at any time. The nullptr is a possible value.
  std::string description;

  // documentation references
  std::vector<DocRef> refs;
  //
  // A block message
  bool isBlock() const { return execWidth == 1 && (isLoad() || isStore()); }
  //
  bool isLoad() const { return lookupSendOp(op).isLoad(); }
  bool isStore() const { return lookupSendOp(op).isStore(); }
  bool isAtomic() const { return lookupSendOp(op).isAtomic(); }
  bool isSample() const { return lookupSendOp(op).isSample(); }
  bool isOther() const { return lookupSendOp(op).isOther(); }
  //
  // An atomic that returns a value
  bool isAtomicLoad() const { return hasAttr(Attr::ATOMIC_RETURNS); }
  //
  // A transpose data layout
  bool isTransposed() const { return hasAttr(Attr::TRANSPOSED); }

  // Enables the operation to be used within a predicate assignment.
  operator bool() const { return hasAttr(Attr::VALID); }
}; // class MessageInfo

static inline MessageInfo::Attr operator|(MessageInfo::Attr a,
                                          MessageInfo::Attr b) {
  return MessageInfo::Attr(int(a) | int(b));
}
static inline MessageInfo::Attr &operator|=(MessageInfo::Attr &a,
                                            MessageInfo::Attr b) {
  return (a = a | b);
}
static inline bool operator&(MessageInfo::Attr a, MessageInfo::Attr b) {
  return (int(a) & int(b)) != 0;
}
inline bool MessageInfo::hasAttr(Attr attr) const {
  return attributeSet & attr;
}
inline void MessageInfo::addAttr(Attr attr) {
  attributeSet = attributeSet | attr;
}

// for legacy encodings where the SFID comes from bits
SFID sfidFromEncoding(Platform p, uint32_t sfidBits);

// The payload lengths for a given message.
// Negative values indicate that the value is unknown or could be variable.
struct PayloadLengths {
  int dstLen = -1;
  int src0Len = -1, src1Len = -1;
  bool uvrlod = false;

  PayloadLengths() {}

  // This attempts to deduce payload lengths from the given inputs.
  PayloadLengths(Platform p, SFID sfid, ExecSize execSize, uint32_t desc);

  // Same as above, but given a Op::SEND*
  //
  // For older platforms this will extract the SFID from exDesc
  PayloadLengths(Platform p, ExecSize execSize, uint32_t desc, uint32_t exDesc);
};

// Organizes various parts of syntax during decoding.  This enables
// formatters to interleave real registers.
//
// LOAD: load, load_strided, load_cmask, fence
//    MNEMONIC SFID CONTROLS
//         $datareg DATATYPE
//         SURFACE [ SCALE $addrreg IMMOFFSET ] ADDRTYPE
// ATOMIC: atomic_iinc
//    MNEMONIC SFID CONTROLS
//         $datareg DATATYPE
//         SURFACE [ SCALE $addrreg IMMOFFSET ] ADDRTYPE
//         $atomic-arg
// STORE: store, store_strided
//    MNEMONIC SFID CONTROLS
//         SURFACE [ SCALE $addrreg IMMOFFSET ] ADDRTYPE
//         $datareg DATATYPE
// CONTROL: e.g. barrier
//    MNEMONIC SFID CONTROLS
//         SURFACE [ SCALE $addrreg IMMOFFSET ] ADDRTYPE
//         $datareg DATATYPE
//
// Examples:
//   load.ugm.ca.ca (32)          r10:d32x4    bti<0x02>[r20-0x40]:a32
//   load.ugm.ca.ca (1)           r10:d32x4t   flat[r20+0x40]:a64
//   load.slm (1)                 r10:d32x4t   flat[r20+0x40]:a64
//   store_strided.ugm.wt.wb (16) bss<a0.4>[r20+0x40]:a32   r10:d32x4
//   atomic_iinc.ugm.un.un (32)   r10:d32   flat[r20-0x40]:a64   null
struct MessageSyntax {
  enum class Layout {
    // unset
    INVALID = 0,
    // e.g. load, load_strided, load_quad, load_blocks2d, ...
    LOAD,
    // e.g. store, store_quad, store_strided, ...
    STORE,
    // e.g. atomic_iinc, atomic_fadd
    ATOMIC,
    // e.g. barrier or eot
    CONTROL
  };
  Layout layout = Layout::INVALID;

  bool isValid() const { return layout != Layout::INVALID; }
  //
  bool isLoad() const { return layout == Layout::LOAD; }
  bool isStore() const { return layout == Layout::STORE; }
  bool isAtomic() const { return layout == Layout::ATOMIC; }
  bool isControl() const { return layout == Layout::CONTROL; }

  std::string mnemonic; // e.g. "load" or "load_block"
  // SFID          sfid;     // e.g. "ugm"
  std::string controls; // e.g. ".ugm.d32.a64.ca.ca"

  // address stuff
  std::string surface;   // e.g. "bti[0x2]", "bti[a0.4]", or "" (flat)
  std::string scale;     // e.g. 4*...
  std::string immOffset; // e.g. -0x40

  // emits rough syntax
  std::string str(std::string execInfo, std::string dataReg,
                  std::string addrReg, std::string atmoicArgReg) const;

  // orders the operands in a symbolic form
  // (suffixes surface, scaling and offset)
  std::string sym() const;
}; // MessageSyntax

//
// Returns the resulting information of a message decode
struct DecodeResult {
  MessageInfo info;
  MessageSyntax syntax;
  DiagnosticList warnings;
  DiagnosticList errors;
  DecodedDescFields fields;

  operator bool() const { return errors.empty(); }
};

// Attempts to decode the descriptor for send instructions
DecodeResult tryDecode(const Instruction &inst, DecodedDescFields *fields);

// Attempts to decode the descriptor for send instructions
DecodeResult tryDecode(Platform p, SFID sfid, ExecSize execSize,
                       uint32_t exImmOffDesc,
                       SendDesc exDesc, SendDesc desc,
                       DecodedDescFields *fields);

static inline DecodeResult tryDecode(Platform p, SFID sfid, ExecSize execSize,
                                     SendDesc exDesc, SendDesc desc,
                                     DecodedDescFields *fields) {
  return tryDecode(p, sfid, execSize, 0, exDesc, desc, fields);
}


//
// returns true if the SFID on a given platform is eligible for symbolic
// translate for load/store syntax; this function enables us to
// incrementally enable load/store syntax
bool sendOpSupportsSyntax(Platform p, SendOp op, SFID sfid);
//
bool isLscSFID(Platform p, SFID sfid);
//
struct VectorMessageArgs {
  SFID sfid = SFID::INVALID;
  SendOp op = SendOp::INVALID;
  int execSize = 0;
  CacheOpt cachingL1 = CacheOpt::DEFAULT;
  CacheOpt cachingL3 = CacheOpt::DEFAULT;
  //
  AddrType addrType = AddrType::FLAT;
  SendDesc addrSurface = 0; // a0 or imm
  int addrScale = 1;        // must be 1x, V*D, 2*V*2, or 4*V*D
  int addrSize = 0;
  int addrOffset = 0;  // imm only
  int addrOffsetX = 0; // block2d only
  int addrOffsetY = 0; // block2d only
  int dataSizeReg = 0;
  int dataSizeMem = 0;
  bool dataSizeExpandHigh = 0; // d8u32h
  union {
    struct {
      short dataVectorSize;
      bool dataTranspose;
      bool dataVnni;
    };
    //
    // used for LOAD_QUAD, STORE_QUAD, ...
    // e.g. this might map to to dc1 untyped read/write ops
    uint32_t dataComponentMask = 0; // x,y,z,w (x-enabled is bit 0, ...)
  };

  ///////////////////////////////////////////////////////////////////////
  // creates an initial empty message
  constexpr VectorMessageArgs() {}

  // returns the logical count of elements per address
  // for simple vector messages, it's dataVectorSize, but for
  // messages with a component mask, it's the number of enabled channels
  int elementsPerAddress() const {
    if (lookupSendOp(op).hasChMask()) {
      int n = 0;
      for (int i = 0; i < 4; i++)
        n += (((1 << i) & dataComponentMask) ? 1 : 0);
      return n;
    } else {
      return dataVectorSize;
    }
  }

  bool isLoad() const { return lookupSendOp(op).isLoad(); }
  bool isStore() const { return lookupSendOp(op).isStore(); }
  bool isAtomic() const { return lookupSendOp(op).isAtomic(); }
  bool hasCMask() const { return lookupSendOp(op).hasChMask(); }
}; // VectorMessageArgs

bool encodeDescriptors(Platform p, const VectorMessageArgs &vma,
                       uint32_t &exImmOffDesc, SendDesc &exDesc, SendDesc &desc,
                       std::string &err);
} // namespace iga

#endif
